Question

21 multiple choice 1 point
coefficients are...
the written forms of chemical reactions.
the relative whole numbers of each species involved in a chemical reaction.
the rearrangement of atoms to produce a new product.
the substances undergoing a reaction.
clear my selection
22 multiple choice 1 point
predict the reactants of the following composition reaction.
box → fes(s)
fe + s
fe₂ + s
fe
s
clear my selection

Explanation:

Question 21

To determine the correct definition of coefficients in chemical reactions:

• "the written forms of chemical reactions" describes chemical equations, not coefficients.
• "the relative whole numbers of each species involved in a chemical reaction" matches the definition of coefficients (they balance reactions by indicating mole ratios).
• "the rearrangement of atoms to produce a new product" describes a chemical reaction’s process, not coefficients.
• "the substances undergoing a reaction" refers to reactants, not coefficients.

Step1: Recall Composition Reaction

A composition (synthesis) reaction combines simpler substances into a compound. For \( \text{FeS}(s) \), we need reactants that form iron(II) sulfide.

Step2: Analyze Reactants

• \( \text{Fe} + \text{S} \): Iron (Fe, elemental) and sulfur (S, elemental) react to form \( \text{FeS} \) (since Fe has a +2 charge and S has a -2 charge, the formula is \( \text{FeS} \)).
• \( \text{Fe}_2 + \text{S} \): \( \text{Fe}_2 \) is not a valid elemental form (Fe exists as Fe atoms, not \( \text{Fe}_2 \) in this context).
• \( \text{Fe} \) or \( \text{S} \) alone cannot form \( \text{FeS} \) (needs both elements).

Answer:

B. the relative whole numbers of each species involved in a chemical reaction.

Question 22